<!--
 * @Author: Bo Cai
 * @Mail: caibo0520@qq.com
 * @Date: 2021-10-07 17:21:14
 * @LastEditors: Bo Cai
 * @LastEditTime: 2021-12-22 22:50:34
-->
<template>
    <div class="app-container">
        <h2 style="text-align: center">发布新课程</h2>
        <el-steps
            :active="1"
            process-status="wait"
            align-center
            style="margin-bottom: 40px"
        >
            <el-step title="填写课程基本信息" />
            <el-step title="创建课程大纲" />
            <el-step title="提交审核" />
        </el-steps>
        <el-form label-width="120px">
            <el-form-item label="课程标题">
                <el-input
                    v-model="courseInfo.title"
                    placeholder=" 示例：机器学习项目课：从基础到搭建项目视频课程。专业名称注意大小写"
                />
            </el-form-item>

            <!-- 一级分类 -->
            <el-form-item label="课程分类">
                <el-select
                    v-model="courseInfo.subjectParentId"
                    placeholder="一级分类"
                    @change="subjectLevelOneChanged"
                >
                    <el-option
                        v-for="subject in subjectNestedList"
                        :key="subject.id"
                        :label="subject.title"
                        :value="subject.id"
                    />
                </el-select>
                <!-- 二级分类 -->
                <el-select
                    v-model="courseInfo.subjectId"
                    placeholder="二级分类"
                >
                    <el-option
                        v-for="subject in subSubjectList"
                        :key="subject.id"
                        :label="subject.title"
                        :value="subject.id"
                    />
                </el-select>
            </el-form-item>
            <!-- 课程讲师 -->
            <el-form-item label="课程讲师">
                <el-select v-model="courseInfo.teacherId" placeholder="请选择">
                    <el-option
                        v-for="teacher in teacherList"
                        :key="teacher.id"
                        :label="teacher.name"
                        :value="teacher.id"
                    />
                </el-select>
            </el-form-item>

            <el-form-item label="总课时">
                <el-input-number
                    :min="0"
                    v-model="courseInfo.lessonNum"
                    controls-position="right"
                    placeholder="请填写课程的总课时数"
                />
            </el-form-item>

            <!-- 课程简介-->
            <el-form-item label="课程简介">
                <tinymce :height="300" v-model="courseInfo.description" />
            </el-form-item>

            <!-- 课程封面-->
            <el-form-item label="课程封面">
                <el-upload
                    :show-file-list="false"
                    :on-success="handleAvatarSuccess"
                    :before-upload="beforeAvatarUpload"
                    :action="BASE_API + '/admin/oss/file/upload?host=cover'"
                    class="avatar-uploader"
                >
                    <img :src="courseInfo.cover" />
                </el-upload>
            </el-form-item>

            <el-form-item>
                <el-button
                    :disabled="saveBtnDisabled"
                    type="primary"
                    @click="next"
                    >保存并下一步</el-button
                >
            </el-form-item>
        </el-form>
    </div>
</template>
<script>
import course from '@/api/edu/course'
import subject from '@/api/edu/subject'
import teacher from '@/api/edu/teacher'
import Tinymce from '@/components/Tinymce'

export default {
    components: { Tinymce },
    data() {
        return {
            saveBtnDisabled: false, // 保存按钮是否禁用
            courseInfo: {
                id: '',
                title: '',
                subjectId: '',
                subjectParentId: '', //一级分类id
                teacherId: '',
                lessonNum: 0,
                description: '',
                cover: '',
                cover: process.env.OSS_PATH + '/cover/default.png',
            },
            subjectNestedList: [], //一级分类列表
            subSubjectList: [], //二级分类列表
            teacherList: [], // 讲师列表
            BASE_API: process.env.BASE_API, // 接口API地址
        }
    },

    watch: {
        $route(to, from) {
            this.init()
        },
    },

    created() {
        this.init()
    },

    methods: {
        beforeAvatarUpload(file) {
            const isLt2M = file.size / 1024 / 1024 < 2
            if (!isLt2M) {
                this.$message.error('上传封面图片大小不能超过 2MB!')
            }
            return isLt2M
        },
        handleAvatarSuccess(res, file) {
            this.courseInfo.cover = res.data.url
        },
        updateData() {
            this.saveBtnDisabled = true
            course
                .updateCourseInfoById(this.courseInfo)
                .then((response) => {
                    this.$message({
                        type: 'success',
                        message: '修改成功!',
                    })
                    return response // 将响应结果传递给then
                })
                .then((response) => {
                    this.$router.push({
                        path: '/course/chapter/' + response.data.courseId,
                    })
                })
                .catch((response) => {
                    this.$message({
                        type: 'error',
                        message: '保存失败',
                    })
                })
        },
        init() {
            if (this.$route.params && this.$route.params.id) {
                const id = this.$route.params.id
                // 记录路由中的id
                this.courseInfo.id = id
                //根据id获取课程基本信息
                this.fetchCourseInfoById(id)
            }
            // 初始化分类列表
            this.initSubjectList()
            // 获取讲师列表
            this.initTeacherList()
        },
        fetchCourseInfoById(id) {
            course
                .getCourseInfoById(id)
                .then((responseCourse) => {
                    this.courseInfo = responseCourse.data.item
                    // 初始化分类列表
                    subject.getNestedTreeList().then((responseSubject) => {
                        this.subjectNestedList = responseSubject.data.items
                        for (
                            let i = 0;
                            i < this.subjectNestedList.length;
                            i++
                        ) {
                            if (
                                this.subjectNestedList[i].id ===
                                this.courseInfo.subjectParentId
                            ) {
                                this.subSubjectList =
                                    this.subjectNestedList[i].children
                            }
                        }
                    })
                    // 获取讲师列表
                    this.initTeacherList()
                })
                .catch((response) => {
                    this.$message({
                        type: 'error',
                        message: response.message,
                    })
                })
        },

        initSubjectList() {
            subject.getNestedTreeList().then((response) => {
                this.subjectNestedList = response.data.items
            })
        },

        initTeacherList() {
            teacher.getList().then((response) => {
                this.teacherList = response.data.items
            })
        },

        subjectLevelOneChanged(value) {
            for (let i = 0; i < this.subjectNestedList.length; i++) {
                if (this.subjectNestedList[i].id === value) {
                    this.subSubjectList = this.subjectNestedList[i].children
                    this.courseInfo.subjectId = ''
                }
            }
        },

        next() {
            this.saveBtnDisabled = true
            if (!this.courseInfo.id) {
                this.saveData()
            } else {
                this.updateData()
            }
        },

        // 保存
        saveData() {
            course
                .saveCourseInfo(this.courseInfo)
                .then((response) => {
                    this.$message({
                        type: 'success',
                        message: '保存成功!',
                    })
                    return response // 将响应结果传递给then
                })
                .then((response) => {
                    this.$router.push({
                        path: '/course/chapter/' + response.data.courseId,
                    })
                })
                .catch((response) => {
                    this.$message({
                        type: 'error',
                        message: response.message,
                    })
                })
        },

        updateData() {
            this.saveBtnDisabled = true
            course
                .updateCourseInfoById(this.courseInfo)
                .then((response) => {
                    this.$message({
                        type: 'success',
                        message: '修改成功!',
                    })
                    return response // 将响应结果传递给then
                })
                .then((response) => {
                    this.$router.push({
                        path: '/course/chapter/' + this.courseInfo.id,
                    })
                })
                .catch((response) => {
                    this.$message({
                        type: 'error',
                        message: '保存失败',
                    })
                })
        },
    },
}
</script>
<style scoped>
.tinymce-container {
    line-height: 29px;
}
</style>